Fig. 6. Time course of HMW-glutenin-subunit expression in endosperm. HMW-glutenin-encoding transcripts in seed sections of the wild type and line E were detected with an antisense probe for the coding region of 1Ax1. The sense probe was used as control for unspecific labelling. Left column, wild-type labelled with anti-sense probe; middle column, wild-type labelled with sense probe; right column, line E labelled with anti-sense probe. (A-C) 5 dpa. Before the onset of expression, no RNA signal is visible in the endosperm. The pericarp and some aleurone cells show unspecific labelling. (D-F) 8 dpa. Onset of expression in endosperm cells, unspecific labelling in the pericarp. (G-I) 10 dpa. Strong expression in wild-type endosperm, whereas the RNA signal in line E is much weaker and mainly concentrated around the nuclei instead of the whole of the cytoplasm. (J-L) 12 dpa. Very weak expression in line E, in contrast to the wild type. (M-O) 16 dpa. The wild type is still expressing strongly, whereas expression in line E has ceased. Bar, 0.5 mm.